Electrical connectors



y 9, 1956 L. J. KAMM 2,748,364

ELECTRICAL CONNECTORS Filed Odt. 20, 1951 6 Sheets-Sheet 1 3| l8 I9 32 V 5 FIG. 3

FIG. 2

IN VEN TOR.

QMZMM May 29, 1956 Filed Oct. 20 1951 L. J. KAMM ELECTRICAL CONNECTORS 6 Sheets-Sheet 2 INVENTOR.

May 29, 1956 J. KA MM ELECTRICAL CONNECTORS '6 Sheets-Sheet 5 Filed Oct. 20. 1951 FIG. 6.

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ELECTRICAL CONNECTORS Filed Oct. 20, 1951 6 Sheets-Sheet 5 LAWRENCE Tl KAMM y 9, 1956 L. J. KAMM 2,748,364

ELECTRICAL CONNECTORS Filed Oct. 20. 1951 I 6 Sheets-Sheet 6 fannentor LAMmENdE v1." KAMM iw wfi mm (Ittorneg ELECTRICAL CONNECTORS Lawrence J. Kamm, Yonkers, N. Y.

Application October 20, 1951, Serial No. 252,333

20 Claims. (Cl. 339-476) This invention relates to electric connectors, such, for 7 example, as those used to connect conductive cables and as rack-and-panel connectors, and to correlated inventions and discoveries appertaining thereto.

This application is in part a continuation of my copending application Serial No. 190,809, filed October 18,

1950, now abandoned.

The invention comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the articles hereinafter described and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Figure l is a top view of one part of a connector cut away to show its elements; Fig. 2 is an enlarged partial section along the line 2-2 Fig. 1 showing details of contact subassemblies;

Fig. 3 is a side view of the part in Fig. 1;

Fig. 4 is similar to Fig. 1 except that it shows a different contact pressure producing means;

1 Fig. 11 is a top view of a contact unit of the female assembly;

v Fig. 12 is a rear view of a contact unit of the female assembly;

Fig. 13 is a side view partly broken away showingthe male assembly;

Fig. 14 is a front view, partly broken away which shows the male assembly;

Fig. 15 is a top view of a contact unit of the male as sembly;

V Fig. 16 is a side view of a contact unit of the male assembly;

Fig. 17 is a side view of a plug-in instrument with the l female member attached;

Fig. 18 is a fragmentary view showing the lever in depressed position; and

Fig. 19 is transverse sectional view of an alternate form of contact unit construction.

In the constructions exemplified, there are provided mating stacks of contact units which are of thin flat laminated construction and are arranged in each stack in parallel spaced relationship, so that the units of a stack may,

' be inserted between units of another stack in a single operation. Each unit carries a plurality of contacts so atent Q as to provide a conductive pattern on one or both sides ment.

we 2? C thereof. Pursuant to the invention, many, if not all, of the units embody a layer of flexible elastic material and a layer of flexible material carrying flexible contacts, so that due to the yielding of the flexible contacts and/or material a very large area of one individual contact will come into engagement with a similar area on a meeting contact, to assure electrical flow even when there is a film on portions of the area. Pursuant to the invention in its more specific aspects, the end portions of the individual contacts are separated by resilient means whereby greater assurance is had that all the contacts will mate effectively when pressure is applied) thereon. This type of construction, moreover, provides greatly-reduced contact resistance during the mating op eration and minimizes any tendency of foreign matter at a given point to interfere with effective electrical flow from one contact to another.

The connector member whose construction is shown in Figs. 1 and 2, is built up of contact units, or rows. Each row is built up of layers. The core layer 1 is of soft material, preferably rubber or cork and rubber mixture. This is covered on both sides with a flexible but inelastic layer 2 such as paper impregnated with phenolic resin. These three layers, cemented together, form as member which is inflexible but which is soft in a direction; through its thickness. The outer layers 3 are the contacts which are also held by cement.

At each end of the row is a hole which permits the row to be stacked with others on holding dowels 5. The rows in a stack are separated by outwardly-resilient spacers 4 such as rubber rings or metal springs.

Two connector parts having this basic construction are engaged by interleaving their rows. The corner notches of the rows prevent the rows of one part from interfering with the dowels and spacers of the other part.

When force is applied to the interleaved stack, contact pressure is established. The soft cores .1 equalize the contact pressure among the contacts of their respective rows by compressing more under those contacts which; tend to bear too much pressure than under the others. If the construction is reasonably accurate this differential compression is small compared to the average compression and the contact pressures are approximately equal.

In Fig. 3 the connector part shown is attached to a fixed equipment and the mating part (not shown) is as sumed to be on a cable. The dowels 5 are mounted on rigid angle 6 which is fastened to panel 11 of the equip An access hole is shown in the equipment. A rigid pressure bar 7 is on the top of the stack of rows. Retaining rings 8 hold the stack assembled. A stud 9 attached to the angle passes through clearance notches in .the rows, through a hole in the pressure bar, and is threaded into nut 10. When the two parts of the conneetor are engaged the nut is tightened thus establishing contact pressure.

If both the inelastic layers 2 and the contacts 3 are made of flexible materials they deform slightly to pro duce true contact over a large area instead of in a single point or line as is the case with conventional rigid contacts. Also they deform around foreign particles thus preventing interference with the establishment of a good contact.

For extremely low contact resistance or for use in cor rosive atmospheres the contacts are plated with silver or; gold or other metal of the desired characteristics. Since the contacts are not subject to abrasion in engagement and disengagement an electroplated layer is adequate and will not wear off. The edge 6 is shown bevelled to guide the row into proper engagement.

Holes may be provided in the core as exemplified at 31 to provide space for soft material displacement under pressure.

Contact terminals 18 and 19 are staggered to facilitate wiring. The terminals 18 have their ends offset to'the left (Fig. 1) into the intervals therebetween, and the terminals 19 have their ends offset to the right into the intervals therebetween. The terminals have holes 32 for the conductors. The terminal design is optional.

It is apparent that if nut ill and retaining rings 8 were removed the stack could be disassembled, the rows wired, and the part reassembled. Thus it is not necessary to wire in a crowded array of terminals.

It is also apparent that connectors of any number of rows can be built up of standard parts, the only components unique to the connector size being the dowels and stud. The number of contacts in a row is arbitrary, the number illustrated being It) on each face.

Figs. 4 and 5 illustrate a different embodiment of the invention in which the pressure is produced by a cam instead of by a stud and nut. is pressure plate 17, cam 15 with handle 16, dowels 13 to which are fastened blocks 12 with pins 14; and on the mating part, dowels 30 in which are stop rings 29. The cable part has bottom bar 26 and cover 20. 23 and 24 arecontact rows on the two parts respectively.

Rotation of the cam in its bearings in the blocks applies pressure to the full length of the stack. The reaction to this pressure is borne equally by the dowels of both parts since the blocks engage the dowels 30 and transmit pressure to rings 29.

Fig. 5 also shows cable 22, cable conductors 21, and equipment conductors 25. The top line of contacts 27 on one part and the bottom line of contacts 28 on the other part are not used, since they have no mating contacts.

Other pressure producing means are also useable. These include toggles and wedges. Another possible variant is the use of a mechanism to remove a spring pressure instead of applying pressure directly.

A similar and even more effective form of construction is shown in Figs. 6l9 wherein there are exemplified a female member 46 and male member 4-1 of generally similar construction. Each of these members comprises a housing 42 formed of a single sheet of metal, preferably deep-drawn, having an end piece 42a with central rectangular opening 43, and sides, 44, 45, 46, and 47. In the housing of the female member there is formed an opening 50 for the reception of an operating arm 51 of a camming lever 52 the camming portion 53 of which lies within the housing and is in the form of rollers 53a and 53b on a shaft 53c which fits into a slot 53d in an inwardly extending portion 532 of lever 52. The lever is pivoted on a pin 53 journaled in the end piece 42a of the housing and smoothness in operation is gained by journaling on the pin 53], rollers 53g and 5311 which are engaged, re-' spectively, by the rollers 53a and 53b.

Along the sides 44 and 45, respectively, of the male member are bent spring spacers 54. Each of severalpof these spring spacers is, in the present instance, part of a two-spacer unit 55 which separates the contact units. The spacers 54 are, in turn, separated by contact units:

'and' the whole is assembled between lugs 56 and 57. A

spacer 54 of the lower unit 55 extends in the present in- I stance below the lowermost contact unit. As willbe seen, each spacer unit comprises a flat portion 61 connecting.

the outwardly tensional spacers 55. The contact units of the female member are similarly spaced by individual spacer units 61a, each in the form of a spring strip cornprising two outwardly tensioned convolutions 61b and two In this embodiment, there In each layer 63 sheets which are laminated to the insulating layers and, filling in the etched-away portions with additional insulating material and setting the latter. As will be seen from Fig. 11, the sheets are so etched that the strips are spaced from each other and are off-set at one end as indicatedat 65 in full lines for the top strips, and at 66 in dotted lines for the bottom strips to facilitate wiring. The olfset portion of each of the strips is formed with a hole 67 for receiving a wire end. These holes 67 are thus arranged in a continuous row without overlapping.

Between the rollers 53a and 53b and the stack of contact units in the female member, in the present instance, there is provided a flat spring 70 which will deflect on heavy pressure, as, for example, seventy-five pounds, and which bridges the ends 71 and 72 of a channel member 73.

The female member 40 comprises, in the present instance, six contact units 75 with spacer 76 therebetween for the reception of the five contact units 77 of .the male member 41. The male contact units 77 are formed similarly to the units 75. The layers 62 and 63 are replaced by a single body 78 of incompressible insulating material in which contacts 78a are embodied and. the units 77 carry on their front edges forward bevelled extensions 79.

As will be seen from Figs. 6 and 13, the housing 42 of the male member, in which the contact units 77 are secured, is itself mounted in a housing 80 which is designed in the present instance to receive cable ends 81 which are soldered at 82 to the contact strip themselves. (See Fig. 7.)

A latch fixed to the outer housing of the male assembly is provided at 90. When camming lever 52 is depressed, the end of the lever handle 51 is engaged by the latch to prevent accidental opening of the camming lever.

A handle 51 of the cam member may be operated manually or, as thru connections 91, from a member, as lever 92, on the panel of an instrument as shown in Fig. 17.

It is often desirable that means be provided to keep the contacts clean. To this end, the contact units of one or both of the contact pairs may, in accordance with the invention, be provided with wiper elements in the form of flexible strips of rubber or fabric firmly secured to the ends. of the contact units and of greater width than the thickness of. the contact units so as to overlap the sides thereof and wipe the sides of the contacts on an opposing unit as the members of the pair are pushed together.

In the present instance, rubber wipers 93 are provided attheends of the units of the male member, as by means of rubber cement as shown at 94, similar wipers 95 are provided at the ends of the interior units 62 ofthefemale member, as by means of rubber cement as indicated at 96.

Since certain changes may be made in the above article and different embodiments of the invention could be made without departing from the scope thereof, it is intendedthat all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An electrical contact member comprising a housing, spaced compressible contact units within said housing, pluralities of contacts thereon, resilient spacer elements in the form of bent-in spring strips disposed betweenthe ends'of said contact units, and a camming element to compress the contact units and press thev contacts thereof against mating contacts as said resilient elements yield to the camming action because of their resiliency.

2. An electrical contact unit comp-rising a compressible elastic member having a sheet-receiving surface, a flexible hard inelastic insulating sheet secured against said surface thereof, and a plurality of flexible contacts lying against theoutside surface of said insulating sheet.

3. An electrical connector comprising assembled tstacks ofspaced contact units of plate-like form, each of at least certain. of said contact units carrying; on its exposed edge .a.:wiper. ofgreater. widththan the thicknessof said'unit.

4. In or for an electrical contact member, a contact unit of plate-like form carrying on its exposed edge a flexible strip wiper of greater width than the thickness of said unit. a

5. An electrical connector assembly comprising a pair of mating groups of superposed spaced multiple-contact units having alined contacts on the sidm thereof, at least certain of said units being transversely compressible and said units being mutually movable in said transverse direction to compress said compressible units and to compact the superposed units to bring said alined contacts into firm engagement, resilient means to separate said units and to maintain said groups in uncompacted condition for easy mating, means generally parallel to said units for transmission of pressure to the contacts thereof, and means to apply pressure to said transmission means to compact said groups when said units are superposed and said contacts aliued.

6. A contact member as set forth in claim wherein said pressure transmission means is resilient.

7. A contact member comprising a plurality of spaced contact units each carrying a multiplicity of contacts on at least one face thereof, means to mount said units for movement in a transverse direction, and compressible spacers normally separating the end portions of said units and resisting said movement.

8. In or for an electrical connector, a layer of soft elastic material, a flexible inelastic supporting layer, a plurality of flexible contacts each lying on said flexible supporting layer, and means for applying compressive pressure throughout sa-id layers.

9. An electrical connector assembly comprising a flexible inelastic insulating sheet having a flat surface, a plurality of spaced flat flexible contact elements arranged side-by-side on said surface, resilient backing means for said sheet, another insulating sheet having a flat surface adapted to face the first-mentioned surface, a plurality of spaced fiat contact elements arranged side-by-side on the last-mentioned surface and adapted to mate with the contact elements on the first-mentioned sheet at a position between said sheets, and means adapted to exert pressure over an area embracing said contact elements to bring said contact elements into positive and effective electrical contact.

10. An electrical connector assembly as set forth in claim 9, wherein there are provided means for connecting conductors to contact elements on at least one of said sheets.

11. An electrical connector assembly comprising a plurality of insulating members each carrying a plurality of electrical contact elements arranged side-by-side and lying against a surface thereof, another plurality of insulating members each carrying a plurality of electrical contact elements arranged side-by-side and lying against a surface thereof, means to mount said members and elements for bringing said insulating members into overlying relationship to bring portions of certain pluralities of said elements on the first-mentioned insulating members into mating engagement with certain pluralities of said elements on said other insulating members, and means to exert such pressure over an area embracing said contact elements as will bring said elements into positive and effective electrical contact.

12. An electrical connector assembly comprising a female contact unit comprising a plurality of insulating supporting members each having a plurality of contact elements arranged side-by-side and lying against a surface thereof, a male contact unit comprising at least one insulating member and having a plurality of contact elements arranged side-by-side and lying against each of a plurality of surfaces adapted to be juxtaposed with the aforesaid surfaces to bring the contact elements on the former into engagement with the contacts on the latter, at least one of each pair of surfaces adapted to be juxtaposed embodying yieldable means over an area substantially commensurate with the contacts thereon, and means to exert on the assembled units pressure over said area to bring said elements into positive and effective electrical contact.

13. An electrical connector assembly as set forth in claim 12 wherein at least one of the insulating members providing a pair of surfaces adapted to be juxtaposed comprises an element backed by said yieldable means.

14. An electrical connector comprising a pair of contact units each of which carry a plurality of contacts, contacts on one unit being engaged with contacts on the other unit by movement in one direction, the contacts on at least one of said pair of units being flexible and the lastmentioned unit embodying a pressure-equalizing layer of soft compressible material positioned to provide a backing for the engaging portions of the individual contacts thereon to equalize the pressure among the engaging portions of the contacts, a flexible inelastic layer carrying at least certain of the contacts of said last-mentioned unit on said compressible material, and means operative in a direction generally perpendicular to the aforesaid direction to produce working pressure.

15. An electrical connector comprising a pair of groups of contact units each of which carry a plurality of contacts, contacts on a unit of one group being engaged with contacts on a unit of the other group by movement in one direction, the contacts on each of at least certain of said units being flexible, and said certain of said units embodying a pressure-equalizing layer of soft compressible material positioned to provide a backing for the engaging portions of the individual contacts thereon to equalize the pressure among the engaging portions of the contacts, a flexible inelastic layer carrying at least certain of the contacts of said certain of said units on said compressible material, resilient means for normally maintaining the units of the groups in spaced relationship for easy mating, and means operative in a direction generally perpendicular to the aforesaid direction to produce working pressure.

16. An electrical connector as set forth in claim 15 wherein certain other units the contacts of which mate with the contacts of said certain of said units embody incompressible backing layers.

17. An electrical connector as set forth in claim 14 wherein one of said units is in the form of a plurality of overlying plug-in means and the other of said units is in the form of a plurality of overlying socket means each having thereon a plurality of contacts adapted to mate when the units are engaged.

18. An electrical connector as set forth in claim 17 wherein there is provided a retaining frame for one such unit and a camming member swingably mounted on said frame and having a camming portion movable between compressing and releasing positions, and means for operating said camming member.

19. An electrical contact assembly as set forth in claim 18 wherein there is provided resilient take-up means opposing the action of said camming member and comprising a spring strip having a length generally commensurate with said series of contacts and wherein said camming portion is disposed substantially centrally thereof.

20. An electrical connector comprising a pair of groups of contact units each of which carry a plurality of contacts, contacts on a unit of one group being engaged with contacts on a unit of the other group by movement in one direction, the contacts on said units being flexible, and each of said units embodying a pressure-equalizing layer of soft compressible material positioned to provide a backing for the engaging portions of the individual contacts thereon to equalize the pressure among the engaging portions of the contacts, a flexible inelastic layer carrying the contacts of said units on said compressible material, and means operative in a direction generally perpendicular to the aforesaid direction to produce working pressure.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Flint June 19, 1883 Neher Sept. 17,1895 Ray July '30, 1929 Bet'ts et a1 July 4, 1933 Spencer NovQ27, 1934 Osterloo May 19, 1942 8 Rivers Dec. 25, Buchanan et a1. May 11, 1948 Koenig Aug. 3, 19 48 Lager Aug. 30, 1949 Munsey Oct. 25, 1949 Bascom Mar. 28, 1950 Auerbach June 13, 1950 Frei Aug. 7, 1951 

